Check out an enhanced module for website blocking in the local version of Safari on your Mac. Specify the addreses for restricting in terms of access and browsing on your machine, as well as a synchronized iOS device and apply the configuration automatically.
The 2021.1 version of about:blank for Mac was available to download on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The actual developer of this free Mac application is frederik dudzik. The application lies within Internet & Network Tools, more precisely Network tools. We recommend checking the downloaded files with any free antivirus.
From the developer:
about:blank is an application that blocks websites in Safari. You specify the websites that you want to block on your Mac or iOS device, and the rules will be synchronized across all your other devices. The rules are based on regular expressions, which allows for fine control over a blocked URL. For example, you can block the landing page of YouTube and still watch individual videos.
You may want to check out more software for Mac, such as FileMaker Server, NetSpot Device Installer or IPNetSentryX, which might be related to about:blank.